(1) Field of the Invention
The present invention relates to a cell holder unit and an electronic device using the cell holder, and, more particularly, to a cell holder unit connectable to another cell holder mounted on a circuit board and an electronic device in which the cell holder unit is connected to another cell holder mounted on a circuit board.
(2) Description of the Related Art
It is uneconomical to design dedicated parts for each of the various types of electronic devices, such as specific-purpose computers, POS terminals, devices for office automation or communication devices. Thus, in many cases, circuit boards having functions required for an electronic device are selected from among commercially available circuit boards, such as so-called PC boards, having various functions, and the electronic device is manufactured using the selected circuit boards. In some of such commercially available circuit boards, back-up batteries for memories and/or internal timers are required. Each of the back-up batteries is used to maintain data in a memory and to maintain an operation of a timer while a main power supply of a circuit board is in an off state.
In general, the back-up cell (e.g., a lithium cell) is set in a cell holder mounted on the commercially available circuit board. The back-up cell is periodically changed or changed during maintenance performed on demand. A position at which the cell holder is mounted on the commercially available circuit board is independently designed by a maker of the circuit board. That is, the commercially available circuit board is not designed for a specific electronic device. Thus, even if commercially available circuit boards have the same function, positions at which the cell holders are mounted on the commercially available circuit boards may differ from each other.
As a result, in an electronic device manufactured using the commercially available circuit board, the back-up cell is not necessarily located at a position at which the back-up cell is easily removed from and set in the cell holder.
For example, as shown in FIG. 1, a POS terminal 30 (an electronic device) is formed. Referring to FIG. 1, a circuit board 12 which is a commercially available circuit board having functions required for the POS terminal 30 and a power supply unit 32 are housed in a lower case 31. A cell holder 14 is mounted on the circuit board 12.
A back-up cell 15 (e.g., a lithium cell) is removably set in the cell holder 14. The lower case 31 is covered by an upper cover 34. A keyboard 41, a printer unit 42 and a display unit 43 are placed on the upper cover 34. A front panel 33 is fixed on a front surface of the lower case 31.
To change the back-up cell 15 which has deteriorated with time, the front panel 33 and the upper cover 34 on which the keyboard 41, the printer unit 42 and the display unit 43 are placed must be removed from the lower case 31 so that the lower case 31 is opened. In a state where the lower case 31 is opened, the back-up cell 15 is removed from the cell holder 14 and a new back-up cell is set in the cell holder 14. That is, complicated work is needed to change the back-up cell 15.
A high-performance cell may be developed. In this case, since the cell holder 14 is directly fixed on the circuit board 12, if a configuration of the developed cell differs from that of the conventional back-up cell 15, the developed cell is hardly used as the back-up cell.